Sprocket.



L. l. JOHNSON.

SPROCKET.

APPLICATION FILED FEB; 16. 1911.

mme@ 161.2111918.

MEE,

1 Louis J. aonnsoiv, or Tannen-acari, INDIANA( restais.

-Speccationof Letters Patent.

Patented renace, raie.-

,051i,igijlialaapplicationfiledApril,27,1916,` Serial No. 93,917. Divided land tlriisepplfieationfnled February 16.

11er?. serial 110,149,915.

To, @Mya/marit may concern: Y

l Be itknown that I, Lorne J. JonNsoN, a citizen of the United States, residingV at lferre Haute, in the coiilnty of Vigo and St'ateof lndiantnhave invented certain new and `useful Improvements in' Sprockets, of which .the following is a` specification. l

.My invention relates to sprockets and i lnelansto attachingthe same to a wheel, such asthe wheelofabicycle. The present ap-Y plicaltien is` a `division of my application SerialNo. 93,91*?iled April 27, 1916motor driven bicycles, `which, describes devices whereby asuitable motor may be `readily andgeflicieiiitly. attached to a bicycle to trans form .the saine into a motorcycle. The sprocket formingfthe` subject-matter of my present .application is intended primarily for attachment tothe wheel of a bicycle to allowethe, sanietobe driven from a motor byv meansbf a,sprocketfehain, although its 'usefulness is not limited. tothisexample.

My abject is.toprovide a,,sprocket-wheel in which the rim isnotrigidly attached-tothe hubiof. the sprocket, but is resiliently secured thereto` by means of. springs constituting a shockabsorbing mechanism; also so formingthesproeket that it vmay readily be installed., onvaiious forms of bicycle or other wheel without; alteration of the latter'. Preferably, the sprocket, when adjusted, engages thespoke-fflange of thehub of the wheel to -'avhichit.is secured, with inner andouter parts of the Sprocket-wheel `construction engaging opposite sides ofthe spoke flange. In order that a clearer understanding of my invention may. be had, attention is hereby directed to the accompanying drawings forming part of this application and illustrating certain embodiments of myv invention. In the drawings `Eigure 11.'e presents a side elevation of a wheel having my improved socket secured thereto, Fig. 2 is a partially enlarged side elevation of a form of sprocket-wheel mounted on the coasterbrake hub of a bicycle, Fig. 3 is a transverse section taken on line 3-3 of Fig. 2, Fig. 4L. is a partial side elevation of a modified form of sprocket-wheel and Fig. 5 is a section on line 54-5 of Fig. 4. Y

Referring to the drawings, the wheel 1 represented as the rear wheel of a bicycle is mounted for rotation on an axle 2 on which is mounted the coaster-brake hub 3. The spokes 4 of wheel l are secured at their Thesprocket 6 Vis provided with a hub i comprising portions 8, 8 secured .together by bolts 9. The radial arms10 are integral with thehub sections 8, 8 and are provided at their outer ends with yokeportionsr 11 in which are journaled rollers 12.`l The sprocket rim 13 provided with teeth 1411 is rotatably mounted on rollers 12. Spiral springs l5 connect arms 10 of the hub secy tions with rim 13, two springs 15 extending in opposite directions from each arm 10.k

These springs permit the sprocket rim 13 to rotate a certain amount in either direction when the motor is first started before the power is v`fully applied through the sprocket to the rear wheel. The springs therefore act as shock-absorbing devices to reduce the shock in either direction when power istransmitted from the internal comb ustion engine to the wheel.

The sprocket is also provided with arrannular clamping plate formed yin two halves 16, 16. The hub sections 8, 8 are mounted 'onthe inner side of the left hand spoke flange of the coaster-brake hub 3 and the clamping ring sections 16, 16 on the outer side of the spoke flange The hubsections are provided with peripheral lugs 17 which engage the adjacent sideof the spoke flange i 5 between the inner ends ofthe spokes 4l, and the Asections of `theclamping'ring y16, 16 are provided with similar projectionsv 1S which are adapted to engage the opposite or outer side of spoke flange 5 between the inner ends of the spokes. Screws 19 extend through the clamping ring sections 16, 16 into the hub sectionsv 8, 8 when the sprocket is assembled to clamp the hub in positlon against the inner Surface of the spoke flange 5 of the coaster-brake hub.l

The hub is also provided with three or more screws 2O which extend radially through bosses on the hub members and engage the coaster-brake hub 3. Clamping blocks 21 may be provided at lthe inner ends of set screws'QO to directly engage hub 3. Screws serve to centralize the sprocket hub and to vprevent lateral strains which yscrews 19, but also is prevented from revolving by the projections 17 and 18 of the sprocket hub and clamping ring coming into contact with the spokes. rIhe sprocket hub, asstated, is made of two parts in order to make installation ofthe same possible without dismantling the bicycle wheel. v'Ihe clamping plate 16, 16 is preferably .divided in sections, as shown, inY order to permit the use ofY the same with various makes of bicycle vand coaster-brake, including coaster brakes which have enlarged ends outside the vspoke flange.Y

A modified form of sprocket is partially yillustrated in Figs.V 4 and 5. In this form, the rim V13 is slidably mounted in guides on the arms of the hub instead of being mounted en'the rollers 12. As illustrated, each arm Y10 is formed at its outer end with an oiset portion 22, a slideway vor guidecfor the rim 13 being formed between portion 22 and a curved plate 28 which may be screwed or f otherwise secured to the arm 10 as shown.

While the'construction has been described .and illustrated as a sprocket having a sprocket-chain running over the same, it'is Y obvious that a belt might be substituted vfor the chain 7, in which case a pulley rim obviously takes the place of the sprocket rim 13. The sprocket described' is adapted to be readily installed on various forms of bicycle wheel, or other spoked wheel, without alteration of the latter, makes possible a substantial application' of power to Va .bicycle or similar wheel, and is so constructed as to prevent strains on l the bicycle or other device with which the wheel is used, by shocks from j the motor. It also prevents the motor impulses'from tending to slip the tire on the rim of the wheel or Von the road, in the case of a bicycle, and acts as a cushion device to absorb the excess force of the motor at the Vtimes of motor impulse.

What I claim is j 1. In a device of the character described,

Y Copies of this patent may be obtained for the combination of a bicycle wheel having spokes and a hub` having a spoke flange, and a sprocket-wheel comprising a hub portion and a clamping plate engaging opposite sides of said flange and secured together, said hub portion and clamping plate having projections extending between the spokes adjacent to their connection with the spoke flange, substantially as set forth.

2. In. a device of the character described, a sprocketewheel adapted to be detachably vsecured to the hub and spoke fiange oi a bicycle wheel, comprising a divided hub, clamping plate and rim supported from said hub, the hub scot-ions having means for scouring them together, said hub and clamping plate having means for drawing them together on opposite sides of the spoke flange, and means for securing said hub to the bicycle wheel hub, substantially as set forth.

3. In a device of the character described, a sprocket-wheel comprising a hub with outwardly extending arms, said arms having yoke portions at their outer ends, rollers journaled in said yoke portions, a sprocket fiange rotatably mounted on said rollers, and springs extending in opposite directions from each arm connecting thc same with said flange, substantially as set forth.

4:. In a device of the character described, a sprocket-wheel adapted to be detachably secured to the spoke-flange of a bicycle wheel, said sprocket-wheel comprising a divided hub with integral outwardly extending arms and means for securing the hub sections together, a rim carried by said arms, a divided clamping ring with means for drawing the same toward said sprocket-wheel hub, with said spoke flange clamped between the same, and set screws extending radially through said sprocket-wheel hub, said hub and clamping ring having projections on their adja` cent faces adapted to engage between the spokes attached to the said spoke flange, substantially as set forth.

This specification signed and witnessed this 13th day of February, 1917.

ve cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

